The purpose of the Tissue and Pathology and Core, which will be located within the Departments of Pathology at Brigham and Women's Hospital, Massachusetts General Hospital, and the Beth Israel Deaconess Medical Center, is to provide to all SPORE investigators with: 1. Research pathology services including expert diagnosticians to confirm diagnoses and ensure consistency in reporting of all human tissue samples utilize by researchers and provide technical and laboratory facilities including a comprehensive range of resource such as immunohistochemistry and in situ hybridization for both frozen and paraffin-embedded material, in situ hybridization, fluorescence based flow cytometry and microscopy for quantitative and qualitative analysis of cell surface and intracellular molecules, computer assisted image analysis, digital imaging, and laser capture microdissection. These facilities will provide SPORE investigators with essential services for diagnosis confirmation and the evaluation of new markers, probes and antibodies. The Core will contain the appropriate equipment, reagents, and technical expertise to provide the services using the facilities described above. Personnel in the Pathology Core will be available to advise investigators on technical aspects of the Core facilities in addition to help with interpretation of results. 2. A Tissue/Blood Repository/Virtual Tissue Bank, including collection, and storage of fresh tissue samples and collection, processing and storage of blood and blood components from patients with malignant melanoma, congenital nevi, cutaneous T-cell lymphoma, cutaneous squamous cell carcinoma, and vascular tumors enrolled in the SPORE-related projects. The Virtual Tissue Bank will link the extensive resources of the Dana Farber/Harvard Cancer Center-associated hospitals. The investigators will therefore be provided with ready access to a wide range of related clinical material with associated clinical information. In the context of all access to a wide range of related clinical material with associated clinical information. In the context of all human tissues, there will be close collaboration between the Tissue and Pathology Core and the Clinical Data Management Core which will assume responsibility for providing and maintaining the clinical databases for Management Core which will assume responsibility for providing and maintaining the clinical databases.